SiC (silicon carbide) is expected to be a material for next-generation power semiconductor devices. SIC has excellent physical properties, having a band gap three times wider than that of Si (silicon), a breakdown field strength about 10 times higher than that of Si, and a heat conductivity about three times higher than that of Si. By taking advantage of those properties, it is possible to realize a power semiconductor device that is low-loss and capable of high-temperature operation.
Meanwhile, it is known that, when a MOS (Metal Oxide Semiconductor) structure is formed on the C-plane of 4H—SiC, a gate leakage current becomes larger as compared to the Si-plane.